Elektromagnetische Umweltverträglichkeit eines Elektrofahrzeugs mit kontaktlosem Ladesystem

Abstract

When developing electric vehicles with wireless power transfer systems (WPT system), the human exposuire with respect to electromagnetic fields (EMF) must be secured. With the help of two newly developed methods, the EMF behavior of electric vehicles with a WPT system can be estimated at an early stage of development by using existing EMC component tests according to CISPR 25. It is possible to consider both reference levels and base restrictions. So that the internal electric field strength can be calculated for a human body model, an extension of an existing field solver by volume integral equations is presented. Later on this method is verified for the human model TARO. The first method models WPT systems from construction data and parameterizes them through a combination of network analysis and the theory of reflected loades. Verification can be carried out through magnetic field measurements during component testing. An EMF assessment of the WPT system can then be carried out in a simulation with the model of a car body. Magnetic fields also occur in the interior of a vehicle. These are mostly caused by the electrical currents of the energy supply systems. The second method presented, the current-based EMF assessment, offers the possibility to achieve a prototype-free development with respect to EMF guidelines. For this purpose, current limit values for each component of interest are first derived from the reference value functions of applicable EMF guidelines in combination with line and car body data of a virtual prototype. These can then be used in a CISPR 25 component test for the EMF assessment of the measured currents.